US1843684A - Process for treating oil - Google Patents

Description

Feb 2, 1932. KIRSCHBRAUN 1,843,684

PROCESS FOR TREATING OIL Original Filed Dec. 23, 1920 Lesfzr Mfsh brawn.

Fatented 2,

ITED STATES LESTER KIRSOHBRAUN, OF LmNIA, NEW JERSEY, ASSIGNOR. TO UNIVERSAL OIL PROD- 'UOTS ('20., OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA.

PROCESS FOR TREATING OIL Application filed December 23, 1920, Serial No. 432,832. Renewed January 13, 1928.

This invention relates to improvements in process and apparatus for treating 011 and refers more partlcularly to improvements in the dephlegmation of the generated vapors subsequent to their passing from the cracking zone.

Among its salient objects is to provide a process in which the enerated Vapors, subsequent to being cracked, are first dephlegw mated in a primary dephlegmator whereby a portion of the vapors are fractionally condensed, the remaining uncondensed portion passing to a secondary dephlegmator where an additional amount of the higher boiling point fractions are separated out; to provide a process in which a more uniform distillate is produced due to the fact that the oil charge does not have to be heated to as higha temperature in order to force the vapors through a dephlegmator of a size suflicient to separate out adequate quantities of the higher boiling point fractions; to provide a process in which, by the insertion of .two smaller dephlegmators, the initial temperature inthe cracking zone may be reduced and a greater part of the wildcat or extremely low boiling point hydrocarbons eliminated; to provide a process whereby the'character of the final'distillate may be regulated by drawing off vapors from different heights'on the dephlegatom according to the atmospheric conditiops'and subsequently subjecting said vapors to a secondary condensing action and drawing the vapors from, the second dephlegmator at regulated heights thereon and finally condensing the uncondensed vapors from the second dephlegmator and collecting the same in liquid form in the receiver; to provide an apparatus for the effecting of this process, and, in general, to provide a process and apparatus of'the character referred to. -The single figure is a side elevation, partly in section, of the ap aratus.

Referring to the rawing-heating coils 1 are mounted in a furnace 2 which is preferably heated by means of gas burners 3. a At 4 is an expansion or vaporizing chamber connected to cracking coils by means of the pipe 5 controlled by a valve 6. This vapor chamber is equipped with-a draw-ofi pipe 7 regulated by a valve 8. Ordinarily, the hot residuum from the vaporizing chamber is directed through the line So controlled by the valve 8?) which line passes through the tank 34 where it acts to assist in preheating the incoming raw oil, or, if desired, it may be diverted through 80 regulated by valve 8d to a coil positioned in the bottom of the secondary dephlegmator 18; A vapor line 9 leads from the top of the vapor chamber to adephlegmator 10 which is equipped with draw-off pipes 11 regulated by valves 12 positioned at difl'erent heights on the dephlegmator for the purpose of 1 drawing ofi the uncondensed vapors. The dephlegmator is equipped with a pressure gauge 13 and a reflux line 14 controlled by a valve 15. A goose-neck 16 regulated by a valve 17 directsthe vapors from the top of the primary dephlegmator to the lower portion of the secondary dephle mator 18. The vapor lines 11 tapped into t e primary dephlegmator at different heights communicate with the vapor line-16. The secondary dephlegmator is similarly equipped with vapor draw-ofi's 19 positioned at various heights thereon identical to the lines 11 in the primary dephlegmator. These draw-off lines 19 are controlled by valves 20. Pressure gauge 21 furnishes a means for ascertaining at all times the. pressure in the secondary dephlegmator. A vapor line 22 controlled by a valve 23 is tapped into the top of the secondary dephlegmator and directs the uncondensed "apors from the secondary dephle mator to the water condenser 24 from whic the distillate flows to a receiver 25. The

'latter is equipped with pressure gauge 26,

liquid level gauge 27, pressure relief p1pe 28 controlled by a valve 29'and a liquid drawoff 30 regulated by a valve 31. The reflux from the secondary dephlegmator is drawn ofl through the line 32 in which is interposed a valve 33 and is mixed with the raw oil which is maintained at a regulated level in the tank 34. The raw oil is introduced to said tank through an inlet pipe 35 and is controlled at a regulated level by means of the gauge 36. After mixing with the reflux which is introduced to the body of the oil through a per-' forated horizontal pipe 37, the raw oil is directed through a line 37' and a pump 38 process is substantially as related in the de 'z scription of the drawing,"the oil being heated in the heating coils 'l and converted to vapors in the vapor chamber 4 from which the vapors pass over to the primary and secondary dephlegmators, as explained.

Atmospheric conditions will regulate to a certain extent which vapor line will be used to draw off the vapors from the primary dephlegmator for introduction to the secondary dephlegmator. In a like manner the selection of the draw-ofl line from the secondary dephlegmator will be controlled by thc character of the distillate desired and the atmospheric conditions which affect the dephlegmation in the secondary dephlegmator. In the vapor lines connecting the primary and secondary dephlegmators are valves, the idea being to cause the first dephlegmation to take place under pressure and the dephlegmation in the secondary condenser or dephlegmator to take place under substantially atmospheric conditions,or slightly above.

In 'a system having but a single dephlegmator, it is diflicult to obtain a ressure distillate of hydrocarbons containing a maximum percentage boiling within the range of gasolene. dephlegmator, which operates under pressure, will produce a pressure'distillate approximating 50 B. gravity and containing from fifty to sixty percent of hydrocarbons boiling within the range of commercial gasolene. Attempts to improve the quality of this distillate by extending the dephlegmator has necessitated greater heat in the cracking tubes in order to permit of more extended rectification, also to compensate for additional radiation, and to develop the additional energy required by the production and storage of the greater amount of vapors dephlegmat-ed under compression. It is apparent that the numerous redistillations which take place during dephlegmation require the storage of more heat in the vapors when carried out under compression than when this operation is conducted under atmospheric pressure. All such additional heat must, of course, be a plied in the cracking zone and the result 0 excessive heating is to produce overcracking and the formation of undesir ably large quantities of very low boiling point or wildcat hydrocarbons, uncondensable gas and carbon.

By operating the disclosed invention, it is possible to produce an improved quality of pressure distillate Without the application of Generally, a system using a singleneaacsa complished by releasing the pressure after the initial dephlegmation and thus utilizing the heat stored up in the hydrocarbons and the energy available with the release of the pressure to produce additional dephlegmation and eliminate the hydrocarbons having a boilin point outside of the gasolene range.

It rom the first stage of dephlegmation there is a 50 B. gravity distillate available for condensation and this distillate is subjectedto further dephlegmation by the dis closed process, it will be apparent that an improved distillate will result in the final condensatiorl'iigzand instead of procuring only fifty to sixty percent hydrocarbons 1n the boiling point range of gasolene, a pressure distillate of about 50f B. gravity and containing from 7 5 to 85% gasolene may be obtamed. A

Exact control may be secured in the second dephlegmating unit by imposing'a relatively low pressure above atmospheric on this portion of the system, should it be desirable at any time to retard the passage of the lower boiling .point hydrocarbons into the receiver.

" This, together with the selection of the proper vapor take-cits, makes it possible to secure this exact control of dephlegmation corporate three or more dephlegmating steps in the system.

' I claim as my invention 1. A process for treating oils, consisting in cracking the oil under a substantial pres sure, dephlegmating the vapors in successive stages of reduced pressure, regulating the character of the final distillate by drawing 1 ofi vapors from each stage of dephlegmation at points in the height of said stages which may be varied as variations occur in the rate of dephlegmation due to atmospheric conditions, condensing the vapors withdrawn.

from the final stage of dephlegrnation, and maintaining a regulated di erential pressure during operation.

2. A process for treating oils, consistin in cracking the oil under a self generate vaporv pressure, dephlegmating the vapors in successive stages under successively reduced' pressure, regulating the character of distillate produced by controlling-the points in the height of each stage of dephlegmation' at which vapors are withdrawn, and condensing. the vapors Withdrawn from the final stage of dephlegmation.

3. A process of treating oil, consisting in I cracking the oil while maintaining it under a self-generated vapor pressure, dephleg mating the vapor produced in an initial dephlegmator under a pressure substantially the same as that maintained during the cracking of the oil, directing the uncondensed vapors to a second dephlegmating stage and there subjecting them to dephelgmation under pressure less than that in the initial dephlegmating stage, condensing the vapors from the second dephlegmating stage, and controlling the distillate produced by regulating the points in the height of the dephlegmator s from which the vapors are Withdrawn, said points bei varied as variations occur in the rate 0 I dephlegmation due to atmospheric conditions. 'LESTER KIRSCHBRAUN.

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